boost/geometry/core/tag.hpp
// Boost.Geometry (aka GGL, Generic Geometry Library)
// Copyright (c) 2007-2012 Barend Gehrels, Amsterdam, the Netherlands.
// Copyright (c) 2008-2012 Bruno Lalande, Paris, France.
// Copyright (c) 2009-2012 Mateusz Loskot, London, UK.
// Parts of Boost.Geometry are redesigned from Geodan's Geographic Library
// (geolib/GGL), copyright (c) 1995-2010 Geodan, Amsterdam, the Netherlands.
// Use, modification and distribution is subject to the Boost Software License,
// Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
#ifndef BOOST_GEOMETRY_CORE_TAG_HPP
#define BOOST_GEOMETRY_CORE_TAG_HPP
#include <boost/geometry/core/tags.hpp>
#include <boost/geometry/util/bare_type.hpp>
namespace boost { namespace geometry
{
namespace traits
{
/*!
\brief Traits class to attach a tag to a geometry
\details All geometries should implement a traits::tag<G>::type metafunction to indicate their
own geometry type.
\ingroup traits
\par Geometries:
- all geometries
\par Specializations should provide:
- typedef XXX_tag type; (point_tag, box_tag, ...)
\tparam Geometry geometry
*/
template <typename Geometry, typename Enable = void>
struct tag
{
typedef void type;
};
} // namespace traits
/*!
\brief \brief_meta{type, tag, \meta_geometry_type}
\details With Boost.Geometry, tags are the driving force of the tag dispatching
mechanism. The tag metafunction is therefore used in every free function.
\tparam Geometry \tparam_geometry
\ingroup core
\qbk{[include reference/core/tag.qbk]}
*/
template <typename Geometry>
struct tag
{
typedef typename traits::tag
<
typename geometry::util::bare_type<Geometry>::type
>::type type;
};
}} // namespace boost::geometry
#endif // BOOST_GEOMETRY_CORE_TAG_HPP